Are the steering wheels the same size?

power steering vanagons have smaller steering wheels.  Manual
steering have bigger steering wheels.

Does the steering rack of 2 metal pipes going to it?  Look underneath
the spare tire area to confirm you have a power steering rack.  If
power, hopefully it is dry and fluid is not leaking out of it.

If everything is equal, check tire pressure again or try swapping
front tires with the other vans.   Tires are easy to steer when new
but get harder as they wear out.  Certain tires (like Michelin
Agilis) are really easy to steer with manual steering.